Methods of performing concurrent fin and gate cut etch processes for FinFET semiconductor devices and the resulting devices
A method includes forming a plurality of fins above a substrate. A plurality of gate structures is formed above the plurality of fins. A first mask layer is formed above the plurality of fins and the plurality of gate structures. The first mask layer has at least one fin cut opening and at least one gate cut opening defined therein. A first portion of a first fin of the plurality of fins disposed below the fin cut opening is removed to define a fin cut cavity. A second portion of a first gate structure of the plurality of gate structures disposed below the gate cut opening is removed to define a gate cut cavity. An insulating material layer is concurrently formed in at least a portion of the fin cut cavity and the gate cut cavity.
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1. Field of the Invention
The present disclosure generally relates to the fabrication of integrated circuits, and, more particularly, to various methods of performing concurrent fin and gate cut etch processes for FinFET semiconductor devices and the resulting devices.
2. Description of the Related Art
In modern integrated circuits, such as microprocessors, storage devices and the like, a very large number of circuit elements, especially transistors, are provided on a restricted chip area. Transistors come in a variety of shapes and forms, e.g., planar transistors, FinFET transistors, nanowire devices, etc. The transistors are typically either NMOS (NFET) or PMOS (PFET) type devices wherein the “N” and “P” designation is based upon the type of dopants used to create the source/drain regions of the devices. So-called CMOS (Complementary Metal Oxide Semiconductor) technology or products refers to integrated circuit products that are manufactured using both NMOS and PMOS transistor devices. Irrespective of the physical configuration of the transistor device, each device comprises drain and source regions and a gate electrode structure positioned above and between the source/drain regions. Upon application of an appropriate control voltage to the gate electrode, a conductive channel region forms between the drain region and the source region.
Typically, fins are formed in a regular array. To define separate transistor devices, the length of the fins may be adjusted and some fins or portions of fins may be removed. For example, a fin cut or “FC cut” process cuts fins in the cross direction. Typically, an array of gate structures is formed above the remaining fin portion after the FC process. Subsequently a gate cut or “CT cut” process is performed to cut the gate structures in the cross direction. Each cut process requires a separate multilayer patterning stack and lithography processes, complicating the process flow and increasing the fabrication time of the semiconductor devices.
The present disclosure is directed to various methods and resulting devices that may avoid, or at least reduce, the effects of one or more of the problems identified above.
SUMMARY OF THE INVENTIONThe following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
Generally, the present disclosure is directed to various methods of concurrently performing a fin cut and a gate cut process for FinFET semiconductor devices, and the resulting semiconductor devices. One illustrative method includes, among other things, forming a plurality of fins above a substrate. A plurality of gate structures is formed above the plurality of fins. A first mask layer is formed above the plurality of fins and the plurality of gate structures. The first mask layer has at least one fin cut opening and at least one gate cut opening defined therein. A first portion of a first fin of the plurality of fins disposed below the fin cut opening is removed to define a fin cut cavity. A second portion of a first gate structure of the plurality of gate structures disposed below the gate cut opening is removed to define a gate cut cavity. An insulating material layer is concurrently formed in at least a portion of the fin cut cavity and the gate cut cavity.
Another illustrative method includes, among other things, forming a product including a plurality of fins defined in a substrate, a plurality of gate structures above the plurality of fins, a cap layer disposed above the plurality of gate structures, and a first dielectric layer having a first top surface coplanar with a second top surface of the cap layer. A first mask layer is formed above the cap layer and the first dielectric layer. The first mask layer has at least one fin cut opening and at least one gate cut opening defined therein. A first portion of the cap layer exposed by the gate cut opening is removed to expose a second portion of a first gate structure of the plurality of gate structures. A third portion of the cap layer exposed by the fin cut opening is removed to expose a fourth portion of a second gate structure of the plurality of gate structures. The hard mask layer is removed. The second portion of the first gate structure is removed to define a gate cut cavity. The fourth portion of the second gate structure is removed to expose a fifth portion of a first fin of the plurality of fins. The fifth portion of the first fin is removed to define a first fin cut cavity. An insulating material layer is concurrently formed in at least a portion of the fin cut cavity and the gate cut cavity.
The disclosure may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTIONVarious illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
The present disclosure generally relates to various methods of performing concurrent fin and gate cut etch processes for FinFET semiconductor devices and the resulting devices. Moreover, as will be readily apparent to those skilled in the art upon a complete reading of the present application, the present method is applicable to a variety of devices, including, but not limited to, logic devices, memory devices, etc., and the methods disclosed herein may be employed to form N-type or P-type semiconductor devices. The methods and devices disclosed herein may be employed in manufacturing products using a variety of technologies, e.g., NMOS, PMOS, CMOS, etc., and they may be employed in manufacturing a variety of different devices, e.g., memory devices, logic devices, ASICs, etc. As will be appreciated by those skilled in the art after a complete reading of the present application, the inventions disclosed herein may be employed in forming integrated circuit products using a variety of so-called 3D devices, such as FinFETs.
The inventions disclosed herein should not be considered to be limited to the illustrative examples depicted and described herein. With reference to the attached figures, various illustrative embodiments of the methods and devices disclosed herein will now be described in more detail.
The substrate 210 may have a variety of configurations, such as the depicted bulk silicon configuration. The substrate 210 may also have a silicon-on-insulator (SOI) configuration that includes a bulk silicon layer, a buried insulation layer and an active layer, wherein semiconductor devices are formed in and above the active layer. The substrate 210 may be formed of silicon or silicon germanium or it may be made of materials other than silicon, such as germanium. Thus, the terms “substrate” or “semiconductor substrate” should be understood to cover all semiconducting materials and all forms of such materials. The substrate 210 may have different layers.
Additional process steps may be formed to complete fabrication of the device 200, such as the forming of metallization layers including interconnects for contacting the various portions of the device 200, such as the source/drain regions 240 and the gate structures 285. The process flow illustrated above has several advantages. Because the fin and gate cut processes are effectuated using a single hard mask, the process flow is shortened, thereby increasing throughput and reducing costs.
The fin cut process may result in the cutting of a gate structure above the fin cut region. In the embodiment of
The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Note that the use of terms, such as “first,” “second,” “third” or “fourth” to describe various processes or structures in this specification and in the attached claims is only used as a shorthand reference to such steps/structures and does not necessarily imply that such steps/structures are performed/formed in that ordered sequence. Of course, depending upon the exact claim language, an ordered sequence of such processes may or may not be required. Accordingly, the protection sought herein is as set forth in the claims below.
Claims
1. A method, comprising:
- forming a plurality of fins above a substrate;
- forming a plurality of gate structures above said plurality of fins;
- forming a first mask layer above said plurality of fins and said plurality of gate structures, said first mask layer having at least one fin cut opening and at least one gate cut opening defined therein;
- removing a first portion of a first fin of said plurality of fins disposed below said fin cut opening to define a fin cut cavity;
- removing a second portion of a first gate structure of said plurality of gate structures disposed below said gate cut opening to define a gate cut cavity; and
- concurrently forming an insulating material layer in at least a portion of said fin cut cavity and said gate cut cavity.
2. The method of claim 1, further comprising removing a third portion of said substrate disposed below said second portion of said first gate structure to extend said gate cut cavity.
3. The method of claim 1, wherein removing said first portion of said first fin and removing said second portion of said first gate structure comprises performing a plurality of etch processes, wherein at least one of said plurality of etch processes is performed using said first mask layer as an etch mask.
4. The method of claim 1, further comprising:
- forming a cap layer above each of said plurality of gate structures;
- forming a first dielectric layer above said plurality of gate structures;
- planarizing said first dielectric layer to expose said cap layer;
- forming said first mask layer above said first dielectric layer;
- removing a third portion of said cap layer exposed by said fin cut opening to expose a fourth portion of a second gate structure of said plurality of gate structures;
- removing a fifth portion of said cap layer exposed by said gate cut opening to expose said second portion of said first gate structure;
- removing said second portion of said first gate structure to define said gate cut cavity; and
- removing said fourth portion of said second gate structure to expose said first portion of said first fin.
5. The method of claim 4, wherein removing said second and fourth portions comprises concurrently removing said second and fourth portions.
6. The method of claim 4, removing a sixth portion of said substrate exposed by said first gate cut opening to extend said first gate cut opening into said substrate.
7. The method of claim 6, further comprising forming a second dielectric layer in a bottom portion of trenches defined between adjacent fins prior to forming said plurality of gate structures, wherein said gate cut cavity exposes said substrate and a portion of said second dielectric layer and has a first depth where it extends into said substrate and a second depth, less than said first depth, where it exposes said second dielectric layer.
8. The method of claim 4, wherein concurrently forming said insulating material layer comprises:
- forming said insulating material layer above said first dielectric layer so as to fill said fin cut cavity and said gate cut cavity; and
- performing a planarizing process to remove portions of said insulating material layer extending beyond said fin cut cavity and said gate cut cavity.
9. The method of claim 4, wherein concurrently forming said insulating material layer comprises:
- forming said insulating material layer above said first dielectric layer so as to fill said fin cut cavity and said gate cut cavity; and
- planarizing said insulating material layer, wherein a portion of said insulating material layer remains above said first dielectric layer.
10. The method of claim 9, wherein said plurality of gate structures comprise a sacrificial material, the method further comprising:
- forming a second mask layer above said insulating material layer, said second mask layer having an opening exposing said insulating material layer;
- etching said insulating material layer through said second mask layer to define a dummy gate cavity therein;
- forming a layer of said sacrificial material in said dummy gate cavity;
- removing said cap layer to expose said sacrificial material of said plurality of gate structures;
- removing said sacrificial material from said plurality of gate structures to define a plurality of second gate cavities;
- removing said sacrificial material from said dummy gate cavity; and
- forming a conductive material in said plurality of second gate cavities and said dummy gate cavity.
11. The method of claim 10, further comprising forming a gate insulation layer in said plurality of second gate cavities and said dummy gate cavity prior to forming said conductive material.
12. The method of claim 4, further comprising removing said first hard mask layer prior to removing said second and fourth portions.
13. The method of claim 1, wherein said fin cut opening abuts said gate cut opening to define a non-rectangular combined opening.
14. The method of claim 1, wherein said fin cut opening has a first dimension extending in a direction perpendicular to a long axis of said first fin and a second dimension orthogonal to said first dimension, wherein said first dimension is greater than said second dimension.
15. The method of claim 1, wherein said gate cut opening has a first dimension extending in a direction parallel to a long axis of said first fin and a second dimension orthogonal to said first dimension, wherein said first dimension is greater than said second dimension.
16. The method of claim 1, further comprising replacing remaining portions of said gate structures with replacement material including a gate dielectric layer and a conductive material disposed above said gate dielectric layer.
17. A method, comprising:
- forming a product comprising a plurality of fins defined in a substrate, a plurality of gate structures above said plurality of fins, a cap layer disposed above said plurality of gate structures, and a first dielectric layer having a first top surface coplanar with a second top surface of said cap layer;
- forming a first mask layer above said cap layer and said first dielectric layer, said first mask layer having at least one fin cut opening and at least one gate cut opening defined therein;
- removing a first portion of said cap layer exposed by said gate cut opening to expose a second portion of a first gate structure of said plurality of gate structures;
- removing a third portion of said cap layer exposed by said fin cut opening to expose a fourth portion of a second gate structure of said plurality of gate structures;
- removing said first mask layer;
- removing said second portion of said first gate structure to define a gate cut cavity;
- removing said fourth portion of said second gate structure to expose a fifth portion of a first fin of said plurality of fins;
- removing said fifth portion of said first fin to define a first fin cut cavity; and
- concurrently forming an insulating material layer in at least a portion of said fin cut cavity and said gate cut cavity.
18. The method of claim 17, wherein concurrently forming said insulating material layer comprises:
- forming said insulating material layer above said first dielectric layer so as to fill said fin cut cavity and said gate cut cavity; and
- planarizing said insulating material layer, wherein a portion of said insulating material layer remains above said first dielectric layer.
19. The method of claim 18, wherein said plurality of gate structures comprise a sacrificial material, the method further comprising:
- forming a second mask layer above said insulating material layer, said second mask layer having an opening exposing said insulating material layer;
- etching said insulating material layer through said second mask layer to define a dummy gate cavity therein;
- forming a layer of said sacrificial material in said dummy gate cavity;
- removing said cap layer to expose said sacrificial material of said plurality of gate structures;
- removing said sacrificial material from said plurality of gate structures to define a plurality of second gate cavities;
- removing said sacrificial material from said dummy gate cavity; and
- forming a conductive material in said plurality of second gate cavities and said dummy gate cavity.
20. The method of claim 19, further comprising forming a gate insulation layer in said plurality of second gate cavities and said dummy gate cavity prior to forming said conductive material.
9412616 | August 9, 2016 | Xie |
20130052781 | February 28, 2013 | Dai |
20140051247 | February 20, 2014 | Cheng |
Type: Grant
Filed: Feb 23, 2016
Date of Patent: Sep 12, 2017
Assignee: GLOBALFOUNDRIES Inc. (Grand Cayman)
Inventors: Ruilong Xie (Niskayuna, NY), Min Gyu Sung (Latham, NY), Catherine B. Labelle (Schenectady, NY), Chanro Park (Clifton Park, NY), Hoon Kim (Clifton Park, NY)
Primary Examiner: Asok K Sarkar
Assistant Examiner: Dmitriy Yemelyanov
Application Number: 15/050,540
International Classification: H01L 21/8234 (20060101); H01L 21/308 (20060101); H01L 21/3105 (20060101); H01L 21/311 (20060101); H01L 29/66 (20060101);